1533859-A is referenced by 13 patents.

1533859 Head-up display ELLIOTT BROS (LONDON) Ltd 27 April 1976 [29 April 1975] 17812/75 Heading G2J A helmet has a display device (light-emitter diode array 33) collimated and presented to the wearer by a prism 37 and the visor 29. The optics are such that spherical aberration introduced by the visor is corrected and preferably astigmatism is also corrected e.g. by modifying the otherwise plane internally reflecting surfaces 41, 43 of the prism.

Headgear incorporating optical display systems
Application Number
GB19750017812 19750429
Publication Number
1533859 (A)
Application Date
April 29, 1975
Publication Date
November 29, 1978
Elliott Bros
G02B 23/10
G02B 27/01
B64D 45/00
A42B 03/00
G02B 27/01
B64D 45/08
A42B 03/00
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